Tractor



G. W. CURTIS April 14, 1953 TRACTOR 6 Sheets-Sheet l Filed Nov. 20. 1944 INVENTQR. @Mz-2 G. W. CU RTIS TRACTOR April 14, 1953 Filed Nov. 20, 1944 6 Sheets-Sheet 2 mmm-mw 6 Sheets-Sheet 5 G. W. CURTIS TRACTOR April 14, 1953 Filed Nov. 20, 1944 IN VEN TOR. ya?, z/vzfz ab BY A TTOJENEVS.

G. W. CURTIS April 14, 1953 TRACTOR 6 SheetS-Shee' 4 Filed Nov. 20, 1944 INVENTOR.

G. W. CU RTlS April 14, 1953 TRACTOR 6 sheets-sheet 5 led Nov. 20, 1944 lllllllllflllll.

April 14, 195s G. w. CURTIS 2,634,663

TRACTOR Filed Nov. 20, 1944 6 Sheets-Shee'l 6 l '15@ I 15' K /a 522/ /43 IN VEN TOR.

Patented pr. 14, 195.3

UNITED STATES PATENT OFFICE TRACTOR George W. Curtis, Wauwatosa, Wis. Application November 20, 1944, Serial No. 564,303

14 Claims.

vThis invention relates to improvements in tractors.Y

I-n the past it has been customary to attach relatively cumbersome and expensive wheeled implements of various types to a farm tractor and these wheeled implements have usually been connected at the rear. More recently some of the tractor manufacturers have manufactured a few implements which have no independent wheels and which can be mounted directly on the tractor. This development has reduced to some extent the implement cost but generally increased the amount of manual work required in assembling-a tractor and a selected implement for a particular piece of work. The farmer still has the problem of manually moving a heavy implement into position, effecting a rigid connection to the tractor, and of adjusting the rear tread width of the tractor to suit the requiremens. This latter operation, with present methods, is very time consuming, as it involves jacking up the rear traction members, and moving or reversing ther position of heavy wheels and tires. Those implements, now available, which are connectable directly to the rear of a tractor, are also objectionable from a number of other angles. In the first place, the implements are provided with a pivot connection for arcuate swinging movemerit in a vertical plane. This is undesirable,

because in obtaining a required depth setting of the implement, the angle is changed as it is swung on the pivot, and this change in angle may detrimentally affect the work. Another objection to present day tractors is that they have a fixed center of gravity of weight. Because of this fact, they' must be designed with this center of gravity far enough forward to prevent rearward overturning of the tractor under certain extreme conditions which are sometimes encountered, particularly when a plow is being pulled. In earlier tractors, Where the center of gravity was not located far enough forward, serious accidents have. occurred in which the tractor has turned over backwards, pinning the operator therebeneath.` Where the center of gravity has been located far enough forward to minimize the possibility of accidents of this nature, there is necessarily 'parasitic' weight 'on the front wheels or steering during most ofthe work for which the tractor isv used. The excess weight causes the front wheels'to sink too deeply into soit soil, and causes too great a packing tendency.

itis ageneral objectof the present invention to provide an al1-purpose tractor which is'so def members, and this weight is a detriment signed as to obviate the above-mentioned objectionable features of prior tractors.

A further object of the present invention is to provide an all-purpose tractor to which wheelless implements, for performing all of the necessary farming operations, as well as auxiliary wheelless bodies, may be quickly attached without manual labor.

is an importan-t factor, may be readily positioned at the front, and other implements such as plows, v

may be positioned at the rear.

A further object of the invention is to provide a tractor as above described havingmeans near the front of the tractor to which drawbar extensions of a rear pulled implement may be attached, the said points of attachment being so located on the tractor 4that the line of draft resistance,

below the center of ground contact of the rear traction members and above the center of ground contact of the front steering members, the said line extending from the rear and passing upwardly between said rear and front members to thus provide greater stability for the tractor. The additional effect of this situation is to favorably increase ground contact pressures, when plowing in hard ground, at a time when such increase is most needed, and the effect is also such that overturning tendencies are positively prevented.

A further object of the invention is to provide a tractor of the class described wherein the tread width at both the front and rear may be quickly and simultaneously altered to suit requirementa, preferably by means under the control of an optive length to meet requirements. With this arrangement it is possible to extend the front portion of the frame a suiiicient distance to accommodate and support a wagon body or wheelless combine directly on the tractor.

- A further object ofthe invention is to provide a tractor of the class described, wherein there are The design is such that the implements may be positioned either at the front or in therear. Thus certain tools such as implements used .i in cultivating where good visibility of the work four ground engaging members, the right hand front member being always in alinement with the right hand rear traction member, and the left hand front member being always in alinement with the left hand rear traction member. Thus the rear traction members run essentially in the same tracks as the front members. This arrangement has obvious advantages over a tractor design wherein there is a single front wheel, or two closely spaced front wheels, which run in a separate track intermediate 'the tracks made by the rear driving wheels A further object of the invention is to provide in a tractor of the class described means for exerting a uniform vertical lifting action on the attached implements as distinguished from an arcuate lifting action. Thus ideal tool performance at any required depth setting is insured.

A further and important object of the invention lis to provide a tractor-.wherein normally only a small amount of thetotal weight of the tractor is carried on the front steering members and wherein there is means for readily shifting the center of gravity orweight to suit requirements forspecial purposes. Thus when plowing is beingTV performed, with the plow attached at the rear, the weight may be shifted forwardly to counteract anyv'overturning tendency. On the other hand, Where a front cultivator is being'used and `where additional weight on the front steering members is undesirable, the weight may be shifted rear- Wardly'tof eliminate the possibility of overloading said steering members and to improve the weight distribution and improve the traction of the -rear driving members. The arrangement may also be such that the total amount of weight may be reduced or increased as desired. As an important feature of the present invention, the shifting of thecenter of gravity may be accomplished either independently of or simultaneously with the reduction of the tread width.

A further` object of the'invention is t0 provide a construction in which a relative vertical movement of the front steering members with respect to--the frame is permitted in order to compensate for any uneveness in the ground. The constructionalso provides foran'automatic equalization of vground contact and soil shearing pressures.

A still further object is to provide a tractor of the class described wherein any or all of the abcvementioned'adjustments, such as the altering4 of the tread width, the changing ofthe effective frame length, the shifting of the Vcenter of gravity, or the raising and lowering of the 'implement platform, either during the 'process of attaching implements or after they have been attached,l may be vperformed automatically under the' control of an operator, without leaving the drivers seat, the said operations being preferably actuated by hydraulic ram mechanism.

The various features of the present invention make .practical a more extensive application of the "mounted implement principle. Thus in addition to providing the usual tractor-operated tillage implements, usually tractor attached, the present invention provides for attaching, transporting, and operating such additional farm equipment as wagons, manure spreaders, combine harvesters andY corn pickers, the latter being furnished Yin the form of relatively inexpensive wheelless attachments. The present tractor is designedtoslide under an implement orauxiliary body,.1ift`the same in the matter of a lift truck,

4 and effect automatic coupling without manual labor. The heaviest implement may, therefore, be picked up, coupled and transported to a desired location without requiring the operator to leave the drivers seat. The lifting mechanism to which the coupling members are attached is located in the front but is accessible from both the front and rear. Thus the same lift platform is employed for both front and rear mounted equipment. Where rvmeans is provided for attaching drawbar extensions of a rear implement to a front platform, a very favorable situation is obtained with respect to minimizing or entirely overcoming any overturning tendency of the tractor. The construction of the present invention provides greater flexibility in adapting the structure to different widths of row crops, provides wider maximum tread widths, narrower minimum tread widths, and the benefits of a four-wheeled type of design in a row crop type of tractor.

Thus the average farm, which `comprises -60ito tillable acres, may be served by a single tractor adapted to cooperate with a complete line of auxiliary equipment. Due to the fact that the auxiliary equipment is all wheelless, it maybe obtained at a minimumiof cost, and the far-mer who heretofore could only aord Va'fewuf the most necessary implements can with the. present invention obtain a complete line. 1n addition, due to the labor saving features of the present invention, the farm work may beperformedwith a material reduction in vrequiredman hours of Work.

With the above and'other objects in viewthe invention consists ofthe improved tractor, fand all its parts and combinations, as set forth in the claims, and all equivalents thereof.

In the accompanying drawings, illustrating. one

complete embodiment of the preferred Yform of the invention, in Vwhich the same'referencenumerals .designate the same parts in all of the views,

Figrl is a plan View of the tractor frame with the power plant and drivers seat removed. The

'e full line position of the parts indicates a'n arrangement having a maximum tread width and center of gravity shifted toward the rear, whereas the dot and dash lines indicate a minimum tread width with the center of gravity shifted inY a forward direction;

Fig. 2 is a sectional view taken approximately on the line 2-2 of Fig. 1, the lift platformsbeing in .elevated position and a kfragment of a rear mounted'implement being .shown in .attached position;

Fig.V 3 is a sectional View taken `on line 3-3vof Fig. 1 indicating the power plant and drivers platformv in position;

Fig. 4 is a fragmentary .plan view similar Ato Fig. 1, but showing the center of gravity shifted` forwardly without effecting a change in the tread width;

Fig. 5 isa fragmentary sectional viewtaken on line 5 5 of Fig. 4;

Fig. 6 is a fragmentary front elevational View, on a larger scale, showing the front of the Weight shifting mechanism;

Fig. 7 is a front elevational view of the mechanism shown in Fig. 1;

Fig. 8 is a fragmentary sectional viewrtaken on line 8-8 of Fig. 1, the front'ground engaging.

member, however, being Vshown .diagrammatically without section. In V.this view the hydraulic equalizing mechanism is shown` in fully collapsed position. Y

Fig. 9 is a View similar to Fig. 8, showing the hydraulic equalizing mechanism operating to project the front ground engaging member downwardly Fig. 10 is a partially diagrammatic view, showing the front hydraulic umts in horizontal section.

Fig. 11 is a sectional view on the line ll-H of Fig. 10;

Fig. 12 is a sectional view also taken approximately on the line Il--i I of Fig. 10 showing different positions of the valves;

Fig. 13 is a fragmentary side view of one of the valve members;

Fig. 14 is a fragmentary side view of another valve member;

Fig. 15 is a fragmentary plan View of the front end of the tractor showing a front mounted cultivator attached thereto, and

Fig. 16 is a sectional view taken on line IB-IB 0f Fig. 15.

taken approximately The frame Referring more particularly to Figs. 1, 2 and 3, the improved tractor includes a pair of longitudinally extending side frame assemblies 2li. Each of the assemblies 2B includes spaced elongated tubular members 2| and 22 which are preferably square in cross section. Telescoped within the tubular members bers 23 and 24. Projecting inwardly and upwardly from each of the members 22, near the rear of the frame, is a bracket 25 having its outer end in the form of a squared sleeve 2B for slidably receiving the end of a transverse tubular frame member 21. When the side frame assemblies 2G are moved from the full line position of Fig. 1 to the dot and dash line position therein, in a manner to be hereinafter described, the sleeves 2B will slide on the transverse member 21 from the full line position of Fig. 1 to the dot and dash line position therein. This will effect a change in tread width from the maximum shown by full lines to the minimum shown by dot and dash lines.

verse frame member 2 and which project forwardly therefrom, support the rear ends of hydraulic cylinders 29.

Weight shifting and tread width changing Referring to Figs. 1 and 2, the cylinders 23 are telescopically received in tubular members having guideway forming members 3&1' connected to their lower sides (see Fig. 6). The members 30 are connected by bottom strap members 3|, and are preferably squared in cross section. A piston 32, movable in each cylinder 29, has a piston rod 33 connected thereto which projects from the forward end of the cylinder and extends through a block 34 and also through a lug 35 projecting upwardly from the forward end of a weight pan assembly 36. Extending rearwardly on each side of the weight pan assembly is a slide 31 which is movable in the adjacent guideway above the member 3U. The blocks 34 at each side of the front end of the weight pan assembly are adapted to be removably connected to the forward ends of the tubular members 30 by bolts 38.

Connected to the top of each tubular member 30 are bosses 39 which support the lower ends of pins 40. The inner ends of arms 4l are pivotally connected to the pins 42, and the outer ends of said arms are pivotally connected, as at 42, to the projecting ends of transverse mem- 21 and 22 are extension memo Brackets 28, which are connected to the transbers 43 on the side assemblies 20; Rigidly con nected to the top of the inner` end of each lof the arms 4l, and pivotal on the pins 40, is an extension 44. The extensions 44 on each side are connected by a rod 45 and the ends of the rods are pivoted to the ends of the extensions 44 to form and maintain a parallelogram arrangement on each side.

Hydraulic fluid admitted to the chambers 46 of the cylinders 29 from hydraulicconduits-.41 (see Fig. 5) will cause the pistons 32 to be moved forwardly. If the bolts 38 are in the inserted position of Fig. 2, then the piston rods .33 will act to shift the weight pan 36 from the full line position of Fig. 1 to the dot and dash line position therein, and at the same time will shift the tubular members 30 in a forward direction. This will exert a pull in a forwardy direction onthe inner ends of al1 of the swing arms 4l to' move the latter from the full line position of Fig. 1

to the collapsed dot and dash line position therein. During such movement the swing armsfwill pull the side frame assemblies 20 inwardly rto the dot and dash line position, with the sleeves 2B sliding inwardly on the transverse Ymember 2l. By reversing the ilow of hydraulic fluid in the cylinders 29, that is by forcing fluid under pressure through the conduits k48 (see Fig. l) which lead to the frontl ends of the cylinders, the pivots may be returned to the full line position of Fig. 1 or to any intermediate position thereof. The conduits 48 may extend forwardly `in the corners of the squared tubes 30 against the out- .Y

side of the cylinders 29. If the bolts 33, which connect the weight pan assembly with the tubular members 30, are removed, then the weight pan assembly mayv be shifted forwardly, as shown in Figs. 4 and 5, without causing a shift of the side frame assemblies 2i) or a change in the tread width.

While the assembly 36 may be attached to ,and` Y operable to cause a shifting of the power plant, to thereby effect additional shifting in weight, itis preferred to keep the and to utilize auxiliary weights 49 in the weight pan which may be increased in number, decreased in number or entirely removed to suit various requirements.

The driving mechanism.

suitably supported on the member 21 and on the rear power unit 50 ternal combustion engine 5I with clutchfand transmission mechanism 52 for driving the rear drive shaft 53. The ends of have a splined connection with rear traction units 54, and the latter members are connected to the side frame assemblies 20. The connection between the ends of the rear drive shaft 53 and the supporting housings 54 for the rear driving or tracti-on units tion of the driving and same as is illustrated and described in my pending application, Serial No. 554,193, filed September 15, 1944, now abandoned. While this type of endless traction member is much to be preferred, it is nevertheless obvious that driving wheels may be substituted therefor wherever this might be desirable.

With the arrangement obvious that when the side transverse frame 4|, that the rear traction units 54 .will also be power .plant stationary drive shaft 53 is a (see Fig. 3) which includes an inthe rear shaft 53 54, as well as the construcj traction units, is theV above described, it is j frame assemblies 20.... are moved inwardly and outwardly by the arms y the; splinedi connectioni betweengthec-f ofi:T thea ferredito-,have-.thefdriyers Seatmmmtedias shown'.

inuFig; 3;... Referring: to.I this.T figura. arms. 5.54 are; pivotally connected to the sides of the.- powerv unit,l azafata 56: 'llieupperrends ofi the; arms. are connectedf to. rock shafts: 5l' on; the.;v underside.- of the; seat 58.. Alfsoiconneet'ed toztheirock shafts; 511 and; depending' therefromv are@ legs 5,9 whichV support; a.. platform- 60.". suitably supported onA the` frameY of. the seat a. position-i.v in; front-i of; the. operatorfis: a.Y control unit.: 6l.. Fornormal. operation: the.J seat-will; be: disposed; in; thee, posi. tion*4 of Fig-i. 35i. However, iff a. relatively large. wagom body.7V oncombinea being carriedi oir the.- liront:-4 off thetractor; then it.. is desirable;l to.: have; theY seatmovablar to: a. higlen position so. that the@ driver nray-fseev over the. body; This. mayfbe; accomplislfiedI by-swingingr the; arms 5.5 upwardly: toward arventical position; As. the arlfnszsvvingY upwardly;. the dogl (i2/oir each: side.. will snap i over.: the= teeth of? an: arcuatefzrack.- 63f. on; each side, and' Willi maintainlv the. seal: in` any desired; position of? adjustment: Suitable,- yielding; means: may' be; employed to: normally.` urge;v each dog into` engagementfwithiactooth.of;the;rack;.

Zine; lonytudinalrjrame adjustment;

movement*- of= the extensionL frames.` 23z and 2t; in.

ay forward: direction; Thus the eiectiye length ofthe frame may beL-materiallyiincreased to meet4 requirements; Tof-return the;frame members to telescopedJ position, itfis; merely: necessary to; reverse' the control`= valve` for,4 the lines Etf andi their drivethetractor` forwardly against. an. obstruction morder tozpush the` extension frame backinto-the-norrna-l position. ofFig.'V 1.

Front end platform lifting, equalzaing andsteerz'ng.

At the frontrendfoffthe vehiclearetwo ground engaging.. steering units. 66 which are prefer.- ablyy in. the., form; oi endless.; tracklaying mem.- belLS; as fully. describedin.. my cofpending, ap-

p1icationS,erialiNo. 554,193g1led September l5;k

19.4%-,novv;abandoned..v Eachunit; is provided `with an;;up ward1y. projecting: trunnion ST (seeA Figs.v

8.ande9); and.each.trunnion.. is rotatable in a housingi 68.. thereabove.. Connected' tothe. forwardi end, of each` housing.,y 68.2 is, aV cylinder (i9,

and-connectedtotherear endof each housing" is.,ar.cylinder TIL. Each. cylinder 69" has an inter mediate..partitionTITI'.Y Aipist'on ,'I; movable in the rearfhalf ofeachylinder 69,` is.connected by a` pistonrod.'I3Lwith a,steering. yoke'- '16. which' op erates; a...l Steering,v crankiv 'I'I-v connected'i to the trnnnion. 61".' A. secondv piston4 15inA the' forward partof; each cylinder Hlis also connectedY by a piston.4 rod;l 1 with the steering yoke i 'I di' When hydraulic fluid, under*control` of; the operatorV atY the controlnnittl; flows-intothe; forward steering cylinder through the conduit'i'l on-onesideY ofgthetractor, `it-willsimultaneously ilow through the, conduit 155" leadingi to therear` steering cylinder'on .thegfother Msider-of-:thetractor.l At the f sametimeluid wi-libe exhausted-fromthefront steeringcylindert on thev$ lastementioned 'side- Hydraulic fluid, Vdelivered under:

through. theiconduit'lf androm: the .rear steenin'gcyIlnder-on thenrstfmentioned.: side through:

the fconduit'. 15.3; rlhis willicause.; steering: of; both: front units 66 simultaneously in one. direction.. Byv reversing' tlie. ow" of; hydraulic uid soi that it is: exhausted: from"v those'` steering cylinders: above mentioned which it entered and so that itw enters; those steering.' cylinders above? men;- tioned from which it was. exhausted, thev piston: 12 anch I5 will; beamovedN ini a; reverse direction andi steering in; the.. opposite direction. will. befv affected.

On the .forwardsideofY theipartition: 'H ineach cylinder B9 is another piston 18. Thisgzpistonis.;

Y suitablyrconnected Joya pistonV rodp 9fto. the ends' of links 80, as at 3l. The other endsofthe/links;l lillk are; pivotally" connectedfV as;l at'.4 821 to. the lower endsfofg.kneeeactionrmembersa. The;same ends? of the knee action memberse: are pivotally'cone nected; to the sides of ther cylinder 69,. as.; at 84'. Rods 35, on both sides of each cylinder have?. their forward ends pivotally' connected to the pivotsL 82.,T and have their rearward .ends pivotally connected, as at 86, tothe lower ends'of.' other. knee action members 31.v The same endsofthe knee action members 87.' are.. pivoted; as at 88;. on pins projecting fromthe sides ofthe. cylinder 'IBL' The. members 80,. 83",A B5' and 8.7 are duplicated on the two sides of each cylinder 69j and lil; Also there is;v identical mechanism on both sides of'I the tractor: Each. chamber 89v is adapted to receive.. hydraulic uid througha line ('see'ig;4 19)', and the line Sil communicates. through the control Valve mechanism withthe. corresponding"mechanism on the other side off the'v tractor in a manner to provide aY solid. column' of hydraulic iluidfree to flow back and` forthV through1they valve between the.. two when. the pressure becomes greater on either unit 65'. and thuscompensatefor uneveness in thegroundE over which thel tractorsis; moving.

Each cylinder lll hasan intermediatepartitlon. 9i", andon the rearward. side of saidrpartition,A and'mova'ble inthe cylind'ei; is a piston 92. The. piston e2 is. connected to a pistonrod andthe outer endof thepiston'rodiis pivotally connes tei. Each linklis p ivotally as 2.1194, with links 95; connected', as at't" (see bell crank lever 91. The pivotal. one. the pins? 88.'

Fig; 2).. to onerend.0f.a. bell crank levers Blare The other end` of: each bell..crank.lever is pivotally connectedrto. onefend of, a link-9.8; andthe other end. oieachlink.. is. pivotally. connected to.,links, QQ. and. |00.. Each.. link. Illiispivoted to theextension.framesy 2li-and..- 213, as. at. I 0Iand. below'the pivot-.thelinks IilIlz are connectedto links |02..v Therupper. ends of; the links I2,are pivotallyconnectedeto links: I .03; and.. Idd.4 The.- lower. ends.. of. each` linkz' |03.; arezl pivoted .to4 the,v extension:` framewZ 3.- and. 2 4;. as: at. I 6.5, and theupperfendof each linkeI 'fispivota lyconnectedto thelower endtofalink mit. @then links. lill. have. their lowerxends p ivotally con nected to y the linksl I lill.' linksfiS; IUJ, ,Illdsand lIits-arefpivotally-` 'connectedf to. the; lifting., platforms; Hi8; The linksfzjusiz defscribed.Y are.` duplicated on.the"two;sidese-of, the; platform I 08; as: is, vclean from-Figiv 1, .and. the-ene-4 tire mechanism is duplicated;onzbothzsideszzoff the:

tractor.

AS1 a V.result ;ofthisaarrangementwhen hydraulic fluidi is-forced1 under:pressurev through the con-v duits I Il-A against .the pistons:` 92T; thef piston: rods: 93'wi1l through'. the linkage.. and leversajustide scribed: cause a movementtofl the?` two lifting-plat@ forms: I 0.8:.' from: thecollapsed i position.A of f Fig:

Theeupper ends .ofrthef Y to the elevated position of Fig. 2 or to any intermediate position.

The hydraulic system Referring now to Figs. 10, 11, 12, 13 and 14, the control unit which is mounted near the drivers seat, includes a casing having Ia high pressure chamber I It in which pressure is maintained by a suitable hydraulic pump and having bores |I| and H2 for receiving valve members |I3 and H4. The v-alve member IIS has an operating handle I I5 and is provided with an equalizing slot |26, which extends longitudinally of the valve member. This slot may be brought into registration with ducts H6 and H1 in the casing to connect the latter. The duct I I0 is connected with the fluid conduit' |09 leading to the cylinder 10 on one side of the tractor to operate the piston 92. The duct I|1 communicates with the fiuid conduit |09 leading to a like location on the other side of the tractor for operating the piston 92. When the valve member H3 is in the position of Fig. H, the equalizing slot vconnects the lines |09 with each other. When the valve member I|3 is partially rotated, as in Fig. 12, to bring the transverse valve duct |21 into registration with the duct H3, it will, through one of the ducts |28, connect the fiuid conduit |09 on one side with the fluid pressure chamber I I0. At the same time another transverse port |29 in the valve member I I3 will similarly connect the duct I|1 with the fluid pressure chamber H0. Thus fluid under high pressure from the central chamber I|0 will ow equally through both lines Idil to actuate the pistons 32 on the two sides of the tractor equally. Thisof course operates to move the platforms |03 simultaneously and equally toward the elevated position of Fig. 2. Wheny the valve member H3 is in the position of Fig. 11, it will serve to hold the lift platforms in a selected elevated position. If the valve member H3 is rotated to bring the second longitudinal slot |32 into registration with the ducts I I5 and I I1, this slot being longer than the slot |26, then there is communication with a discharge or atmospheric pressure chamber H0. When in this position, the weight of an implement on the platforms |03 will force the pistons 92 back to the position of Fig. 9 t0 return oil from the cylinders through the lines |09 into the oil chamber IIS', which may connect with a suitable reservoir of the oil pump.

The manually operated valve member i4 may be rotated by means of thehandle ISI to control the flow of hydraulic fluid to the equalizing cylinder bores 8S in the cylinders 63. The valve member II4 has a longitudinal slot |32 which 'is of suflicient length to connect the ports |33 and ld leading to the hydraulic conduits 30. When the longitudinal slot |32 is in the position of Fig. 1l, the fluid may flow without restriction from bore 89 on one side of the tractor to the other through the conduits 90, ports |33, |34 and slot |32, and thus the fluid pressure in the space 80 on one side may be equalized with the iluid pressure in the space 89 on the other side. When the valve member I I4 is partially rotated to bring the transverse slots |35 and |36 into a position in which they connect the ports 33 and |34 with the ducts |31,

then fluid under pressure from the high pressure chamber I I0 may ow equally to the spaces 29 in the cylinders 69 to force the pistons 18 in an outward direction. This will operate on the links 80 and levers 83 and 81 to cause a relative downward movement of the steering unit 50 from a partially collapsed position or a. fully collapsed position such as Fig. 2 or Fig. 8 toward the .position of Fig. 9. When the valve is in the firstmentioned position, that is in a position in which the slot |32 registers with the ducts |33 and |34, then an automatic upward retraction of unit 66 on one side may take place simultaneously with the downward extension of unit 65 on the opposite side during operation over uneven ground which provides a vertical front steering'member action similar to the knee action on an automotive vehicle. By turning valve II4 to a position of Fig. 12 whereV the long slot |38 connects'the ducts |33 and |34 with the low pressure chamber H0', the units t6v on the two sides are permitted to collapser simultaneously by gravity.

Flexible conduits 90, |00, 12 and 15 extend from the front hydraulic assembliesto thecontrol unit 6|, so that there is no interference during relative movements of the parts. It 1s preferred to have these conduits extending into receiving boxes |38' and then longitudinally through the tubular frame members 23 and out of the rear end thereof, as shown in Fig. 1. These flexible conduits then extend into the tubular transverse frame member 21 and emerge from the center thereof from which position they can be readily connected to the control unit GI.' vThe hydraulic conduits 64, which supply fluid for the longitudinal frame adjustment, also extend into the transverse tubular frame member 21' and emerge from the center thereof and then extend to the control unit 6I. The hydraulic conduits 41 and 48 for operating the weight shifting and tread width changing mechanisrn may connect directly with the control unit.

Implement coupling Each of the lift platforms |08. has its front end formed with a pair of projecting lugs |39 (see Fig. 1). At the rear end of each platform, referringto Fig. 16, is a coupling mem-ber |40 having a front opening |4I. A coupling dog |42 is pivoted to the member |40, as at |43, and is normally held yieldingly in coupling position by a suitable spring. The dog may be releasably locked in latching position by a sliding plunger |44, normally urged inwardli7 by a spring |45 yand controlled by a wire or cord |46 leading to the drivers seat.

In Figs. 15 and 16 there is illustrated a front mounted cultivator which comprises side frame members |41 and front transverse members |43. The cultivating tools |40 project downwardly from the transverse members |48. Near. the forward end of each of the side frame members |41 is a depending lug |50 having a pin I5I which projects from each side thereof. At the rear end of each side frame member |41 of the cultivator is a forked extension |52 with a transverse pin |53 (see Fig. 16).

With the cultivator supported on a suitable rack, the front end of the tractor may be driven forwardly underneath the cultivator, the tractor platforms |08 being positioned beneath the side frame portions |41 of the cultivator. The operator on the drivers seat of the tractor may then operate the handle H5 on the control unit to cause lifting of the platforms until they properly engage the lower sides of the cultivator side frames I4. Then by driving forwardly `again a short distance, the front lugs |33 of the platforms will embrace the lugs |50 depending from the cultivator frame with the transverse pins |54 engaging beneath the platform lugs |39, as

i l i .shown inFig.` 16. .At V"the .same time itlre rear l pins [53' on the --cultivator will icont'act the :dogs :M2 :forcing the isarne upwardly :until "the C.pins :snap .into .proper iposition, .by :reason of said Aspring. tension, in .the 4.rear vcciiniling :members 1411, :as shown `in Fig. .16. .During this' operation, .plungers '|44 rare held in withdrawn position.

- 4'I-'he :plunger cords .|46 are then .released 4Ito :ner-

. bindihe lugs [3 9 :at the'front-of eachliftplatform :|188 lare transversely extending depending plates .LEZ .and 1.63. These plates :are :spaced nnarnfas shownin Fig. 2. 'When .the platforms Sarejn the'lnwered position zof .3, the plates embrace n. transverse bar |64., connecting the front ends vof the longitudinal side frame memiaersr23 -and 24, and `said vtransverse :bar rhasv an .integral depending bracket portion. `Iii. The front plate |62 projects .downwardly a .substantial distance and is Aprovided near :its lower end with fan :opening in which fa transverse :contact roller `.rti is mmmtecr Whether the platformis in the loweredpositlon of Fig. ,-3 .or in. vthe :raised Y ',:position of Fig. vr2, :the roller y| 5.5 always engages the :bracket |65 or bar |64 so .that the v'pulling -or pushing :strains are transmitted from the .im-

plements :through the platforms |98, plates r|52, rollers |66, brackets |65 to the frame members 23-25 and yin turn to the :relatively strong side frame assembliesl.

Buring use :the drawbar resistance of .an implement is transmittedto theframes los through the couplings 1'39 and m0, Ifno other means were provided, this drawbar resistance would Vbe transmitted 'to `the frames "23 .and T24 through thearms 95, .91 'to |00, T02 to f4, EUG and f'i. .These arms, however, are `preferably :made `of relatively lightgauge and yieldable material and .are not intended to withstand the full stresses that the drawbar resistance would exert thereon. "In addition, vthe pivotal connections of 4said arms have a certain amount "of necessary ;play which would be undesirable in .a draft transmitting connection but which :is necessary for smooth elevating operation.

'In order to prevent the elevating linkage from 'having `any substantial horizontal drawbar .stresses exerted thereon, the rigid plates ,|52 -having rollers |66 which are in 'constant thrust contact with the rigid plates |65 areprovidedto transmit 'substantially all A'horizontal 'drawbar Y stresses between the platforms m8 and the frames 23 and 24.

The platforms |08 larejintended to operate at .the lowest possible position permitted by the 'implement attached (thereto. 'For example, the .-plowshownin Fig. .3 is .so designed that when it is ,inits deepest plowing condition 4the platforms .U18 may be disposed fin their lowermost posi- `tion, as shown in Fig. 3. Since the rollers |66 .transmit the major share of 'the horizontal drawbar .resistance .to .the .plate |65 at the point B when the ,platforms .|08 vare disposed as .shown .sin Fig. .3, the weighted tractive effect or draw- Mvbar ,line .effect necessarily approaches the plane t -of the line `AB which entends .below 'the point -Clunder ythe .deepest plowing rendition.. he'a'c- 'tual line of drawbar resistance.wiilfvarywith :the location of the implement and of the platforms |88; however, it is "inten-ded that the imple- .ment-s -creating the heaviest drawbar .loads be designed so .that the platforms v|1118 tand .the .rollers |615 maybe .positioned their .lowermost positions .shown .inlEig `3 during use therewith, in order .to`jbring .thev .drawbarline to.a. poi'n'.l .helow the point LC when theheaviest loads arebeingpulled.

.It is an important featuren .the .present in- Mention .that .when .a rear plow .'is being pulled, as .at .|.6.I"., Fig. i3, 'that .the line olf draft resistance may be. so located as Lto :or Bn- .tirely prevent Aany Voverturning tendency. the present invention the eeotive ...attachment point, for .the purpose o'f determining the line .of draft resistance A 'isintended to .approximate the point 'B '(Fig. '3) where Ithe roller .contacts the bracket 1.65. The planeof .thelineof draft resistance passesi'from .the 'tool atan inclinellpwardly, Lbelow the .center of ground .contact C of 'the rear traction 'members and .above the `center .of ground contact 1D of the .ir-ont. .steering members. `-.With the plane of the line .fof draft resistance, extending as indicated' at SA, vand below the point IC, any overturning ftendvency is reduced to a minimum.A Alsolb y having thejplane indicated at A pass'belowthe point C, ground -Contact v.pressures are favorably fin- Acreased when most needed.l This .increase iin 'ground contact pressures takes .place .automatically. For example, Ywhen ,plowing [in hard ground, 'the ground Contact .pressures Iare '1ncreased in proportion to 'the :resistance encountered by the piow. 'Furthermoreno matter'how much resistance is encountered b y the plow, or no xn-amer what type of incline `the 'tractor is operating on, overturning .tendencies are Asubstantially prevented because Vof the location of the line 'of draft resistance.

Referring `to Fig. :15, vone :row of planted corn or other crop is .designated .at |54 :and :another row at |155. `The cultivating .tools .1:49 are so arranged that they will cultivate between the two rows land .on the outside of "both row v|515 and row |55. The front .steering members and' the rear traction members are of course in alinement and will operate 'between the rows. Prior to starting the rcultivating operation, the side irameassemblies 2l] of the tractor maybe .moved inwardly or outwardly to suit requirementsrand to iit the particularimplement In addition, the 4center fof gravity may be .shifted .by moving weight pan 36 and weights e9 to the rear .or full line position of '1. This is desirable during cultivating with a -iront .mounted implement, because additional weight on the :front steering member '68 is Aundesirable during 'this type of operation.

All of the other mounted implements may be furnished and equipped with lugs |50 and .transverse pins ll, yas Well .as with rear coupling pins |53 which are positioned to rcooperate with the coupling members on lthe platforms I 08.

Where it is desired .to carry a Wheelless wagon body or a combineharyester on the vfront of .the tractor, the longitudinal extension frame members 23 and 24 may be .moved forwardly toincrease the effective length of .the tractor and at the same time the main side .frames .2. may be positioned to .provide any tread Width desired between the minimum and maximum to .obtain proper .sdeWise stability Jfor the lparticularload ers seat 58 in the manner per unit of tractor conditions involved. These special bodies may then be coupled in the same manner as heretofore described in connection with the cultivator.

By having provision for mounting implements at the front, perfect visibility is insured. This is particularly important in cultivating so that the operator can see that the cultivator is operating in a proper position between the rows. When relatively large bodies are mounted on the front, then it is desirable to raise the drivheretofore described, so that the driver can see over the body.

Referring now te Fig. 2, implements doing work at the rear, such as plows, may be coupled to the same lift platforms i. Each rear implement, such as the plow, is provided with a pair of spaced draw bar members 55, each having an extension i?. The front end of each extension is hooked downwardly, as at 58, and provided with a transverse pin E59 which is engageable beneath the spaced front lugs 139 of the lift platforms, as shown. Each of the draw bar portions |56 is bifurcated, as shown in Fig. 2, with a transverse pin I6!) extending between the bifurcations.

With the plow or other rear connected implements supported on ya suitable rack, the tractor may be backed into position until the draw bar portions |51 are over the lift platforms ESS.

vThe tractor is originally backed a little farther inwardly than the final position, and after the platforms have been adjusted to the proper height, it is driven forwardly to cause engagement of the pins S beneath the lugs 39, and of the pins IEB with the coupling members IM.

In Fig. 2 the lift platforms 68 are shown with the plow in elevated position to clear the ground.

In Fig. 3 the dot and dash lines iti indicate an elevated or carrying position of the plow, and the full line position iti indicates a tilling position. It is apparent that with both front and rear mounted implements, that due to the straight vertical movement of the platforms Illl and the rigid connection of the implements thereto, the implements may be raised or lowered in straight up and down directions. Thus ideal tool operating positions may be obtained at any of the various depth settings. With present day implements, which are attached by swinging connections to the tractor, each time the depth setting is changed, the angularity of the tool in the ground is also changed which is a marked disadvantage.

It is apparent from the above that an all-purpose tractor has been provided to which wheelless implements for performing all of the necessary farming operations, as well as auxiliary wheelless bodies may be quickly attached without `manual labor while the operator is in the drivers seat. It is also apparent that through the novel hydraulic controls, the driver may quickly adjust the effective length of the tractor, the wheel tread width, and the center of gravity to meet the requirements of a particular piece of work. During use the front steering members B6 will always be in alinement with the rear traction members 54 so that only two tracks are made inthe soil. By utilizing the improved tracklaying units of my pending application, Serial No. 554,193, in conjunction with a tractor of this design, heavy loads may be carried with comparatively low, automatically equalized, ground contact pressures, thus providing low soil shearing stresses and a high ratio of tractive effort weight. The design also permits the carrying of a considerably greater proportion of the total tractor weight on the driving members when this is desirable. Thus improved driving traction is obtained, and the possibility of the tractor turning over in use is minimized. The total amount of weight carried in the weight pan may be increased or decreased, as desired, and this weight may be shifted forwardly or rearwardly, either simultaneously or independently of the adjustment of the tread width to meet particular requirements. During use of the device, automatic equalization of ground contact and soil shearing pressures is provided due to the novel knee action of the knee members 83 and Sl. In addition, the front steering units may be simultaneously raised or lowered, relative to the frame, and under the control of the operator whenever this may be required for special conditions.

Reference is also made herein to my pending application, Serial No. 477,559, filed March 1, 1943, now Patent No. 2,416,679, wherein there is disclosed a tracklaying unit. In this application features of the tread width adjustment are disclosed but not claimed.

Various changes and modifications may be made without departing from the spirit of the invention and all of such changes are contemplated as may come within the scope of the claims.

What I claim is:

1. An agricultural device comprising: a ground engaging implement having an elongated connection member forming a drawbar for the implentent, a tractor having a frame, a horizontally disposed platform, elevating means positioned to movably connect said platform to said frame for movement above said frame in such a manner that allrportions of the platform are moved substantially the same distance when Asaid elevating means is operated, means for operating said elevating means to raise or lower the platform, said elongated implement connection member being positioned on top of said platform while the ground engaging implement is at one end of the tractor frame, and complementary means on said elongated portion of the connection member and platform positioned to detachably connect said member on top of said platform.

2. In a tractor having a frame, horizontally disposed platform structure having an upper surface, elevating mechanism positioned to movably connect said platform structure to said frame for vertical movement above said frame, implement couplings on the upper surface of said platform structure above said frame, means for operating said elevating means to control the vertical position of said platform structure, a depending plate rigidly connected to the platform structure above said frame and having a portion extending below said frame, a depending bracket on the tractor frame adjacent and parallel to said plate, and Contact means operable in any position of adjustment of said platform structure for transmitting draft resistance from said plate to a part o f said bracket located belowsaid frame and platform.

3. In a tractor having a frame, horizontally disposed platform structure having an vupper surface, elevating mechanismpositioned to movably connect said platform structure to said frame for vertical movement above said frame, imple- Y ment couplings on the upper surface of said platform above said' frame, means for operating said elevating means to control the vertical position mosaicos tof said ,platfdrms'tructura a depending plate l rig'idly connected .to lth'eiplatform'structure:above :saidframe land :havingja portion 'extending be- Y :lowssaid frame, :a depending bracketnn the trac- ;tor :frame :adjacent and parallel `.to said plate, and airoller on 'said plate Acontacting said bracket fand epositioned to engage the bracket vbelow Ysaid power rmeans for 'causing extensible movement e'of said extension frame, a 'horizontally disposed platform-structure, felevating means positioned to movably connect 'said platform 'structure .to .said extension `frame forlvertical movement Sabove. said lframe., implementzeoupling members on saidgplatform structure, traction means supporting said :frame portion, and ground engaging Vmeans supporting 4saidextension frame.

5. `In :a tractor having spaced longitudinally extending frame portions, an extension frame `connected to each frame portion ffor extensible movement, uid pressure mechanism 'for 'causingextensible:movement of said extension frames, .a .horizontally Vdisposed platform for each extension frame, elevating means positioned 'to movablyconnect each platform-tc its extension frame for vertical movement above said extension frame, implement coupling members on said platforms, traction means-supporting said spaced frame por- `tions, vanda groundlengaging member supporting each extension frame.

6. yInatractor having a prime mover, a frame ,portion-supporting `said prime mover, spaced Vframe vportions laterally adjustablyconnected to lsaid `first mentioned frame portion, a vertically movable Vcoupling member on each of said spaced -frame portions. lfluid pressure operated lmecha-- nism-forlaterally,moving-said spaced frame portions .to adapt the spacing between said coupling members thereon to particular requirements, and ground engaging means supporting said spaced `frame portions.

7. In a tractor Yhaving a prime mover, a frame portion supporting said prime mover, spaced longitudinally extending side members laterally ad'iustably connected to said frame portion, an extension :member connected to each side member for extensible movement, fluid pressure operated vmechanism for causing extensible movement of said extension members, a vertically movable coupling on each extension member, ground engaging means supporting said spaced 'side members, ground engaging means support- "ing 'each extension member, and fluid pressure operated mechanism yfor laterally adiusting said spaced side members to adapt the spacing between the coupling members to particular `requirements.

8. In a tractor having a prime mover, a frame j portion supporting said prime mover, spaced longitudinally extending Aside members laterally adjus'tably connected to said frame portion, an extension member connected to each side .mem- 'ber for extensible movement, Afluid pressure operated mechanism for causing extensible movement of said extension members, a horizontally .disposed ,platform for each extension -memben elevating means positioned to movably connect Y each of .said platforms to ,its extension member for lvertical Vmovement above said extension member, .a coupling on #each platform, ground vengaging means supporting -said .side members,

Y .ground engaging `means supporting each extension member, 4mechanism for A operating 4said elevating imeans .to raise or @lower the platforms and the coupling vmembers thereon, and :fluid pressure operated mechanism for laterally adjusting said spaced-side members to adapt Ithe spacing between the coupling members to particular requirements. l

9. In a tractor ihaving `a frame, horizontally disposed platform structure; elevating .means disposed tomovably connect said platform'structure to `said frame at the front thereof for Vertical :movement of said ,platform above :said

frame; implement couplings on said :platform structure above "said frame; rmeans for operating said elevating means to control the `position of vsaid platform structure; ya `depending `plate rigidly connected to the front end of the platform 4structure above said frame and having a portion extending below said frame; a vdepend- -ing bracket xed to the frontend of the tractor lframe 'behind said plate; and means operable in any :position of adjustment of said platform for transmitting draft resistance `from said plate :to a part of said bracket located below `saidffrarne 'and 'said platform.

10. In a tractorhaving a frame, horizontally disposed platform structure; elevating means disposed to ymovably-connect said platform structure to said frame at the front thereof for vertical movement of said platform above said frame; implement couplings on said platform structure above said frame; means for'operating said elevating means to control the yposition of said platform structure; a depending'plate rigidly connected t0 the front end of the platform structure above said frame and having "a `portion extending 'below said frame; a depending bracket fixed to the Vfront end of the tractor frame behind said plate; and contact means near the lower end of `said plate for transmitting draft resistance to said bracket at-a location substantially below the tractor frame when the platform structure is in lowered position.

-l'l. In a ltractor having a main frame, having a prime mover, and having ground engaging traction means, an auxiliary frame connected to said main frame for movement laterally thereof elevating linkage connected to said auxiliary frame; implement couplings connected to said elevating linkage for vertical movement above said auxiliary frame; fluid pressure operated mechanism for moving said auxiliary frame laterally relative to said power unit; and power means for operating said elevating linkage, whereby said couplings may be moved to a selected vertical vand lateral position Yin accordance with requirements.

12. In a ltractor rhaving a frame, having a prime mover, and having ground engaging traction means` said frame having a longitudinally extensible portion; elevating linkage connected to the extensible portionof said frame; implement coupling means connected to said elevating means for vertical movement above said frame; iuid `,pressure operated mechanism for causing lextensible movement of said extensible frame portion; and power means for operating said elevating linkage, whereby lsaid coupling means may be Amoved to a selected vertical -and longitudinal Yposition in accordance with requirements.

1.3. In a .tractor -having :a lmain frame, .having :a prime mover, and having fground engaging traction means, `an auxiliary frame connected zto said main frame, said auxiliary frame having a longitudinally extensible portion and being connected to said main frame for movement laterally there-of, elevating linkage connected to the extensible portion of said auxiliary frame; implement couplings connected to said elevating linkage for vertical movement above said frame; uid pressure operated mechanism for moving said auxiliary frame laterally relative to said main frame; uid pressure operated mechanism for causing extensible movement of said auxiliary fluid frame; and pressure operated mechanism for operating said elevating linkage, whereby said couplings may be moved to a selected longitudinaly lateral and vertical position in accordance with requirements.

14. An agricultural device comprising a ground engaging implement having an elongated drawbar; a tractor having a frame; a horizontally disposed longitudinally extending elongated platform above said frame; elevating means at the forward end of said frame positioned to movably connect said platform to said frame for vertical movement above said frame; power operated mechanism for actuating said elevating means to raise or lower the platform; said elongated implement drawbar being positioned longitudinally on top of said platform, and projecting rearwardly with said ground engaging implement at the rear of the tractor frame; and longitudinally spaced sets of complementary coupling members on said drawbar and on said platform positioned to detachably connect the drawbar on top of said platform.

GEORGE W. CURTIS.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Jackson Nov. 20, 1894 Knudsen Mar. 19, 1918 Leadbeater Sept. 3, 1918 Druessel Nov. l2, 1918 Manly Dec. 2, 1919 Flood July 19, 1921 Hurtig Nov. 29, 1921 Burtnett June 6, 1922 McKinnon June 13, 1922 Chappell et al. May 19, 1925 King et al. Dec. 2, 1930 Bickerton June 9, 1931 Parrett Dec. 5, 1933 Brown July 24, 1934 Brown et al. May 21, 1935 Kramer Mar. 31, 1942 Blanchett Feb. 16, 1943 Gurries Mar. 16, 1943 Geraldson July 18, 1944 Briscoe Dec. 19, 1944 Kuehlman et al. Dec. 3, 1946 FOREIGN PATENTS Country Date` France Nov. 15, 1920 Great Britain Nov. 21, 1918 Sweden Dec. 12, 1944 

